Q&A

Subject: Senso trial period

From: FD

I have a Senso ( Widex) hearing aid. I have it for a trial. It seems I am having problems with it when I use my digital cell phone (long sound and loud whistle). I can't hear the other person at the other end. Is there something I can do regarding this? I have tried to put the phone further from my ear, tilted it, etc, but it does not help. Is there anything I can do the fix this, or should I go back to an analog hearing aid? Also is there a cross over available for ITC. can you reply asap, for my trial period ends soon. Thanking you in advance, FD

Phil would like to answer this one since he has Senso's and uses cell phones:

Hi FD,

First of all, get back to your audiologist to get the problems fixed before your adjustment period is over. If they are still working on the aid, the adjustment (trial) period will most likely be extended.

There are two issues here:

First: Digital Cell Phones. There are several different brands and modulation techniques in use. I personally wear Widex Senso CIC digital aids and use Cellular One brand digital cell phones (both Nokia and Erickson) without any problems. However, there are other types of digital phones that I haven't tried myself. Some use frequency hopping techniques to spread the signal over a wide range of frequencies. If the hopping rate is slow enough, you may be able to hear it in your hearing aids. This is a big problem with non-digital hearing aids, but digital ones are supposed to be less sensitive to the problem. With non-digital aids, the interference sounds like a cat purring, or a helicopter hovering.

Second: The whistling sound. All hearing aids may whistle when you put a flat object like a deck of cards up against your ear. The better (tighter) the fit of the aid, the less this will be a problem. Some cell phones are flat, sort of like a deck of cards. Regular phones usually have an ear cup, which is much less likely to cause the whistling. Feedback whistle is caused by the sound from the receiver (loudspeaker) part of the hearing aid (down inside your ear) leaking out around the hearing aid and being bounced back into the microphone of the aid, causing feedback and whistling. CIC (completely-in-the canal) style aids are better at avoiding the phone feedback problem.

Now the Widex Senso digital aid has an active feedback preventing circuit. When it senses feedback, it reduces the gain at that frequency and gets rid of the feedback. It needs a few seconds to do this however. So, if that is your problem, and if for some reason your audiologist can't get your aid to fit better, just hold the phone steadily against your ear for a few seconds and the feedback should quit. When you move the phone, the whistle may start up again for a few seconds. I suspect that your new hearing aids don't fit tight enough or have too big a vent hole. These are things that your audiologist can fix.

Some newer digital hearing aids (like the Widex Inteo, for example) have active feedback algorithms that sense the feedback and substitute an out of phase signal to cancel it out. These circuits are almost instantaneous, but you should still hold the phone steady against your ear.

If your problem is truly with the phone, try switching phone brands. I personally would rather have a good digital hearing aid, even if I had to change phones. You use your hearing aids all the time, and your cell phone only occasionally.

Phil